The architecture of node is divided into three layers: 1. Display layer, responsible for processing display; 2. Business logic layer, responsible for processing data from the display layer, or obtaining data from the server for processing and returning to the display layer. ;3. Data access layer, responsible for calling data from the database.
The operating environment of this article: Windows 10 system, nodejs version 12.19.0, Dell G3 computer.
The three-tier architecture literally means that there are three different layers of structures, and each layer is responsible for different data or processes different data. The three-tier architecture is to conform to the idea of "high cohesion, low coupling". Someone asked what is high cohesion and what is low coupling
High cohesion
The stronger the correlation among the elements within the module, the higher the cohesion and the stronger the unitarity of the module. A module should complete a certain function independently as much as possible. If it is a low-cohesion code module, it will be very troublesome to maintain
Low coupling
There are dependencies between modules. As a result, changes may affect each other. The closer the relationship, the stronger the coupling, and the worse the module independence.
The three layers are the presentation layer (display layer), business logic layer (data layer), and data access layer (persistence layer)
Presentation layer (display layer)
As the name suggests, it is the layer that is only responsible for processing the display. In nodejs, it is mainly responsible for receiving the data passed to the server from the page and processing the data. Return
Business logic layer (data layer)
The layer mainly responsible for processing data, which is to process the data of the display layer, or obtain the data of the server for processing Then return to the display layer
Data access layer (persistence layer)
The layer mainly responsible for calling from the database. This layer is to operate the database such as: obtaining data, Editing data, adding data, and deleting data are all processed in this layer
If you want to separate the front-end and back-end development, then A three-tier architecture must be used. For front-end engineers, they do not know much about the backend technology. It is better to use nodejs, which is familiar to front-end engineers, for development.
In nodejs we will refer to express. Configuring the background, the above only shows the three-tier architecture, which is probably not the specific files of the project
Our overall folder is divided into above. dao, rotates, service, this is our three-tier architecture
dao-data layer
The db.js in the folder allows us to connect to the server
The model specifically accesses the server for operations
And xxxDao.js calls methods in the model layer to perform specific operations
Our data layer is processed After the data, the dao layer will return the obtained data or results to the service layer
service-data processing layer
service will perform further processing and then process the processed data The data is returned to the router
ui layer (router)
ul layer renders the data to the page html
Recommended learning: " nodejs video tutorial》
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